Enterotoxigenic E. coli (ETEC) are important bacterial pathogens causing worldwide morbidity and mortality. Enterotoxigenic E. coli infections are important causes of death in infants and children under the age of five in developing countries. Illness caused by an enterotoxigenic E. coli infection is often self-limiting, lasting about one week. However, the illness can range from a mild diarrhea with little to no dehydration to a very severe and potentially fatal cholera-like disease, particularly in infants. Enterotoxigenic E. coli are also the leading cause of diarrhea in travelers to high-risk areas.
Despite our good understanding of ETEC virulence factors, and although several potential ETEC vaccines tested in volunteer trials and field studies, no safe and effective vaccine is yet available for at-risk individuals. Safe and effective ETEC vaccines would have a considerable public health impact worldwide in infants in developing countries, in travelers from industrialized countries to the developing world, and for the military.